Patents by Inventor Kyoung Ik Cho

Kyoung Ik Cho has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20020081795
    Abstract: A method for manufacturing a trench-gate type power semiconductor device is provided A drift region having a low concentration of a first conductivity type and a body region of a second conductivity type are formed on a semiconductor substrate having a high concentration of the first conductivity type A trench is formed using a nitride layer pattern and a sidewall oxide layer formed at sidewalls of the nitride layer pattern as a mask, and then the sidewall oxide layer is removed The corners of the trench are rounded by performing a heat treatment in a hydrogen atmosphere A source region having a high concentration of the first conductivity type is formed using the nitride layer pattern as a mask. The nitride layer pattern is removed, and an upper oxide layer pattern is formed to cover a predetermined portion of the source region and the gate conductive layer.
    Type: Application
    Filed: December 26, 2001
    Publication date: June 27, 2002
    Inventors: Jong-Dae Kim, Sang-Gi Kim, Tae-Moon Roh, Jin-Gun Koo, Dae-Woo Lee, Kyoung-Ik Cho
  • Patent number: 6411542
    Abstract: A ferroelectric memory device including a single ferroelectric transistor that one unit memory cell is independently selected and programmed, when the unit memory cell is programmed for “the first state” or “the second state” by applying a DC bias voltage to the single ferroelectric transistor's gate and well. In addition, the ferroelectric memory device can be applied with normal power level Vdd and GND. The ferroelectric memory device includes a plurality of unit memory cells which are arranged in a matrix, by crossing at least one word line in a column direction with a plurality of bit lines and source lines in a row direction and is connected between the source line and the bit line.
    Type: Grant
    Filed: October 1, 2001
    Date of Patent: June 25, 2002
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Yil Suk Yang, Byoung Gon Yu, In Kyu You, Won Jae Lee, Kyoung Ik Cho
  • Publication number: 20020067114
    Abstract: A field emission device using carbon nanotubes grown in a direction parallel to a substrate and a method of manufacturing a high definition field emission display using an edge emitting luminescent thin film. The device includes a process of selectively depositing a metal catalyst on a sidewall of the pattern to grow the carbon nanotube in a direction parallel to the metal catalyst and a process of attaching the grown carbon nanotube on the main board by application process, so that it can be freely applied in a subsequent process. The device employs a carbon nanotube field emission emitter and an edge emitting in a high fine luminescent body deposited in a thin film type. Thus, a close relationship with the substrate can be maintained due to the horizontally grown carbon nanotubes, a subsequent semiconductor process can be freely applied using a thin film type luminescent body, and a high fine field emission display can be thus manufactured.
    Type: Application
    Filed: May 31, 2001
    Publication date: June 6, 2002
    Inventors: Sung Yool Choi, Kyoung Ik Cho
  • Publication number: 20020064927
    Abstract: An apparatus for forming Strontium-Tantalum-Oxide films and a method thereof using an atomic layer deposition tool are provided. In the Strontium-Tantalum-Oxide films deposited by using plasma and the atomic layer deposition, its leakage-current is very low, and its dielectric constant has a range of 30 to 100 depending on the there heating conditions. Therefore, the method provides structures for i) an insulating film of an NDRO-type ferroelectric memory device that has a structure of Metal-film/Ferroelectric-film/Insulating-film/Silicon, ii) a gate oxide film substituting for silicon oxide film, and iii) an insulating film of Electro Luminescent Display (ELD) device.
    Type: Application
    Filed: May 31, 2001
    Publication date: May 30, 2002
    Inventors: Won-Jae Lee, In-Kyu You, Yil-Suk Yang, Byoung-Gon Yu, Kyoung-Ik Cho
  • Publication number: 20020060312
    Abstract: The present invention provides a green phosphor for fluorescent display having a composition represented by a chemical formula: xZnO+(2-x-y/2)Ga2O3+yAl2O3: zMn2+ where 0.8≦x<1.0; 0<y≦0.8, and 0<z≦0.1, wherein a part of gallium in nonstoichiometric zinc gallate base is substituted for aluminum and Mn2+ is added to the zinc gallate base. Also, the present invention provides a method of manufacturing said green phosphor for fluorescent display, the method comprising steps of: preparing a mixture by mixing uniformly zinc oxide, gallium oxide, aluminum oxide, aqueous solution of manganese oxide or manganese salt and a predetermined solvent; preparing a compound by heating said mixture; and reducing said compound by re-heating said compound in a reducing atmosphere.
    Type: Application
    Filed: February 2, 2001
    Publication date: May 23, 2002
    Inventors: Kyung Soo Suh, Seung Youl Kang, Jin Ho Lee, Kyoung Ik Cho, Ick Kyu Choi, Yong Jei Lee, Jae Dong Byun
  • Patent number: 6373184
    Abstract: Provided with a phosphor for a fluorescent display that includes at least one divalent transition metal and at least two trivalent metal added to SrTiO3 and having a formula of: SrTi1−x−yMxNyO3:zPr3+ wherein M represents the divalent transition metal selected from the group consisting of Zn, Mn, Co, Ni, Cu and Cd, N represents the trivalent metal selected from the group consisting of Ga, Al, In and B, and 0≦x≦0.1, 0≦y≦0.1 and 0≦z≦0.1.
    Type: Grant
    Filed: November 5, 1999
    Date of Patent: April 16, 2002
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Kyung Soo Suh, Jin Ho Lee, Kyoung Ik Cho, Jae Dong Byun
  • Publication number: 20020030646
    Abstract: In the field emission display device in which an electric field emission device is applied to a flat panel display device, an upper plate and a lower plate are vacuum-packaged in parallel, and the lower plate is constructed by row and column signal buses made of metal capable of performing a matrix addressing and by pixels defined by the row and column signal buses, and each pixel is constructed by a film type field emitter, a control device for controlling the film type field emitter and an addressing device for transferring scan and data signals of a display to the control device. Further, the control device is composed of a switching device for directly controlling field emission current of the film type field emitter and a memory device for maintaining the data signal of the display, and the upper plate is made up of anode electrode for accelerating, as high energy, electron emitted from the field emitter, against the field emitter, and a phosphor for performing a cathode luminescence.
    Type: Application
    Filed: December 8, 2000
    Publication date: March 14, 2002
    Inventors: Yoon-Ho Song, Moon-Youn Jung, Seung-Youl Kang, Jin-Ho Lee, Kyoung-Ik Cho
  • Publication number: 20010044251
    Abstract: A cathode structure for a field emission device, which is an essential component of a field emission device, and a method of fabricating the same are provided. An emitter material for electron emission constituting cathodes is formed in a particulate emitter, the particulate emitter is formed of a material from which electrons can be easily emitted at a low electric field. A significant advantage of the present invention over a conventional art is that the present invention patterns an emitter material to a cathode electrode using a photolithography process or a lift-off process. In the lift-off process, the emitting compound is patterned using a sacrifice layer. Also, in another embodiment of the present invention, there is disclosed a method of easily fabricating cathodes for a triode-type field emission device using a particulate emitter material at a low process temperature.
    Type: Application
    Filed: May 17, 2001
    Publication date: November 22, 2001
    Inventors: Young-Rae Cho, Jin-Ho Lee, Yoon-Ho Song, Seung-Youl Kang, Moon-Youn Jung, Kyoung-Ik Cho, Do-Hyung Kim, Chi-Sun Hwang
  • Patent number: 6307323
    Abstract: A field emission display in which field emission devices are applied to a flat panel display. A field emission display with diode-type field emitters includes an upper plate and a lower plate, the upper plate and the lower plate are vacuum-packaged in parallel. The lower plate includes a plurality of column signal buses and a plurality of row signal buses, film type field emitters, and switching devices. The column signal buses and the row signal buses are made of metallic material. Pixels are defined by the column signal buses and the row signal buses. A film type field emitter and a switching device are formed inside each pixel. The switching device controls the field emitter on the basis of scan signals and data signals. The scan signals and data signals are loaded to the switching devices through the column signal buses and the row signal buses. The switching device includes at least three electrodes for connection with the column signal bus, the row signal bus, and the field emitter.
    Type: Grant
    Filed: December 29, 1999
    Date of Patent: October 23, 2001
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Yoon Ho Song, Jin Ho Lee, Seung Youl Kang, Kyoung Ik Cho
  • Patent number: 6261145
    Abstract: The present invention relates to a method of packaging a field emission display. The method of packaging a field emission display, comprising the steps of: forming an opening on a selected area of a lower substrate on which field emission elements are formed and forming a silicon layer on a lower surface of said lower substrate; combining a upper substrate, on which a transparent electrode and luminescent material are formed, and said lower substrate by a lateral wall; placing a cap on said opening after performing a vacuum process through said opening; performing a thermal treatment process so that said cap is combined with said silicon layer by silicide created by the reaction of said cap and said silicon layer, thereby sealing said opening; and completely sealing said opening by adhesives.
    Type: Grant
    Filed: November 25, 1998
    Date of Patent: July 17, 2001
    Assignee: Electronics and Telecommunications Research Institutes
    Inventors: Jin Ho Lee, Ju Youn Cha, Kyoung Soo Suh, Kyoung Ik Cho
  • Patent number: 6204608
    Abstract: A field emission display device is disclosed. The device comprises an upper plate and a lower plate that are vacuum-packaged in parallel, wherein the lower plate is composed of matrix-addressable pixels, wherein the pixel formed on an insulation substrate comprises a field emitter array, a control thin-film transistor having a drain connected to an emitter electrode of the emitter array, and an addressing thin-film transistor having a drain connected to a gate electrode of the control thin-film transistor. Designing the control thin-film transistor to have a large parasitic capacitance between the source and the gate, one can obtain an active matrix display having a memory function and eliminate a conventional complex fabricating process of a memory capacitor, thereby simplify a panel fabricating process remarkably and largely increase the aperture ratio of a pixel.
    Type: Grant
    Filed: November 18, 1999
    Date of Patent: March 20, 2001
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Yoon Ho Song, Jin Ho Lee, Seung Youl Kang, Sung Yool Choi, Kyoung Ik Cho
  • Patent number: 6139760
    Abstract: Provided with a method of fabricating a 200-250 nm short-wavelength optoelectronic device, which has a combination of an optical device with a plurality of acceleration electrodes and a field emission device with a plurality of acceleration electrodes, from a semiconductor having a 5-6 eV energe band gap, based on a principle that an electron-hole pair is produced using a highly energetic electron which is injected from a field emission device, and short-wavelength photons are emitted when the electron recombines with the hole and confined in a quantum well to emit a light corresponding to the energy level of the quantum well, thereby eliminating the need of using dopants for forming n-p junctions in the semiconductor and achieving high efficiency in terms of energy because highly energetic electrons result in one or more electron-hole pairs.
    Type: Grant
    Filed: August 6, 1998
    Date of Patent: October 31, 2000
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Kyu Hwan Shim, Sung Woo Choi, Mun Cheol Baek, Kyoung Ik Cho, Hae Gwon Lee
  • Patent number: 6137219
    Abstract: A field emission display having an n-channel high voltage thin film transistor is disclosed. According to the present invention, a signal for driving pixels controls by the nHVTFT attached with each pixel, therefore, the signal voltage of row and column drivers is exceedingly decreased. As a result, it is possible to implement a field emission display capable of providing a high quality picture in a low consumption power, a low driving voltage and inexpensive to manufacture, and preventing a line cross talk using the nHVTFT. By using a cylindrical resistive body underlying a cone-shaped emitter tip, the present invention is to provide a field emission display having an excellent contollability and stability of the emission current, and a dynamic driving capability.
    Type: Grant
    Filed: July 27, 1998
    Date of Patent: October 24, 2000
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Yoon Ho Song, Jin Ho Lee, Seung Youl Kang, Kyoung Ik Cho, Hyung Joun Yoo
  • Patent number: 6124147
    Abstract: The present invention relates to a semiconductor device and, more particularly, to a short-wavelength optoelectronic device and a method for fabricating the same. The optoelectronic device according to the present invention doesn't have to employ an ion implantation process and an ohmic contact to make the n-p junction in the WB compound semiconductor, providing a sufficient efficiency for display. The method according to the present invention comprises the step of a) forming a SiC:AlN super lattice multilayer by alternately forming a SiC epitaxial film and an AlN epitaxial film on a substrate, wherein the AlN film is formed and the SiC film is formed using a single source gas of 1,3disilabutane in an nitrogen plasma-assisted metalorganic molecular beam epitaxy system; and b) applying a thermal treatment to the SiC:AlN super lattice multilayer, thereby a mixed crystal compound having (SiC).sub.x (AlN).sub.1-x quantum wells obtained by a diffusion of SiC film and AlN.
    Type: Grant
    Filed: November 19, 1998
    Date of Patent: September 26, 2000
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Kyu Hwan Shim, Mun Cheol Paek, Kyoung Ik Cho
  • Patent number: 6073578
    Abstract: The object of the present invention is to provide a RF induction plasma source generating apparatus which generates a stabilized plasma and sustains the stabilized plasma by maintaining the plasma pressure from several hundreds Torr to several thousands Torr with attachment a buffer nozzle cap, upper metallic blocking films and lower metallic blocking films to a nozzle cap, plasma tube and RF induction coils, respectively for separating the plasma source generating apparatus from the chamber.
    Type: Grant
    Filed: December 4, 1998
    Date of Patent: June 13, 2000
    Assignee: Electronics and Telecommunications Research Insitute
    Inventors: Kyu-Hwan Shim, Mun-Cheol Paek, Kyoung-Ik Cho
  • Patent number: 6069018
    Abstract: A method for manufacturing a cathode tip of electric field emission device includes depositing conductive layer and undoped silicon layer on the insulator substrate sequentially; forming a tip-mask pattern on the selected area of top of said undoped silicon film and etching said undoped silicon film isotropically and then anisotropically in turn, so that the silicon film is formed as cone-like having cylinder; and removing the tip-mask pattern, implanting ion into the etched silicon layer and removing the ion implanted silicon layer using the wet etch process.
    Type: Grant
    Filed: August 27, 1998
    Date of Patent: May 30, 2000
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Yoon-Ho Song, Jin Ho Lee, Kyoung Ik Cho
  • Patent number: 5953580
    Abstract: A method of manufacturing a vacuum device utilizing a sputtering process is disclosed. According to the present invention, the vacuum device includes a silicon substrate. An emission electrode having a sharp ended tip is formed by etching the silicon substrate. An insulating layer is formed on the silicon substrate so as to make the entire structure of the emission electrode to be exposed, with the emission electrode being surrounded by the insulating layer. A gate electrode is then formed adjacent to the sharp ended tip of the emission electrode. According to the present invention, it has advantages that the emission electrode is manufactured by forming the silicon pillar using the isotropic etching and anisotropic etching and the gate electrode can be easily formed adjacent to the emission electrode by using the sputtering method after the gate insulating layer is formed.
    Type: Grant
    Filed: September 8, 1997
    Date of Patent: September 14, 1999
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Sung Weon Kang, Jin Ho Lee, Kyoung Ik Cho, Hyung Joun Yoo
  • Patent number: 5939833
    Abstract: The present invention relates to a field emission display which applies a field emission device (or field emitter) to a flat panel display. The field emission display in accordance with the present invention has the lower plate in which the pixel array and the scan and data driving circuits are integrated one insulating substrate, therefore, it is possible to implement a field emission display capable of providing a high quality picture in a low price. The voltage is applied to the scan and data driving circuits may considerably decrease through the tin film transistor attached to each pixel. The field emission characteristics are stabilized by the resistor attached to the field emission device so that reliable field emission display may be fabricated. Further, since all the processes are carried out at a low temperature, a glass, which is low in price and has a large area, may be used as an insulating substrate.
    Type: Grant
    Filed: October 15, 1997
    Date of Patent: August 17, 1999
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Yoon-Ho Song, Jin-Ho Lee, Kyoung-Ik Cho, Hyung-Joun Yoo
  • Patent number: 5314833
    Abstract: A method of manufacturing a GaAs field effect transistor comprises depositing a silicon thin film 202 on a semi-insulating semiconductor substrate 201, forming a first sensitive film 203 by a photolithography to define channel areas and ion-implanting n-type dopants into the substrate to form an activation layer, removing the first sensitive film, forming a second sensitive film 203a on the silicon thin film by photolithography to define an ohmic contact area and then forming a highly doped impurity layer on the side of the activation layer by way of an ion-implantation process, depositing a passivation film 206 over the entire surface of the substrate 201 after the removal of the sensitive film, and effecting an annealing or heat treatment, forming a third sensitive film of a predetermined pattern by using an ohmic contact forming mask, effecting a recess etching process to the surface of the substrate and forming an ohmic contact on the etched portion, and patterning a gate region by using the gate forming
    Type: Grant
    Filed: December 23, 1992
    Date of Patent: May 24, 1994
    Assignee: Electronics & Telecommunications Research Institute
    Inventors: Kyung-Ho Lee, Kyoung-Ik Cho, Yong-Tak Lee